Self-cleaning and sterilizing medical tube

ABSTRACT

The self-cleaning and sterilizing medical tube may include a combination of an endotracheal tube or a tracheostomy tube and a suction catheter that decreases the tendency of mucus and bacteria to adhere to the inner surfaces of the thereof. The medical tube may have a hydrophobic surface exhibiting the lotus effect, which may be formed either by femtosecond laser etching or by a coating of poly (ethylene oxide). Alternatively, the medical tube may be formed with a photocatalyst incorporated therein or have a lumen coated with a photocatalyst. The medical tube may also have a light source and a fiberoptic bundle mounted thereon, the optical fibers extending into the lumen to illuminate the photocatalyst.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/785,592, filed on Apr. 18, 2007, now pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to medical tubes, and particularly to anytype of self-cleaning and sterilizing medical tube.

2. Description of the Related Art

In human beings, mucociliary action regulates the flow of mucus acrossthe layers of epithelial cells within air passages. For example, when aperson experiences breathing difficulty or occlusion, an endotrachealtube is often inserted within the person's air passage. The endotrachealtube, however, interferes with the cilia of the epithelial cells, thusdisrupting the mucociliary action. This often causes the accumulation ofmucus about or within the endotracheal tube. This accumulation of mucusnot only occludes the endotracheal tube passage, but can result in theaccumulation and adhesion of bacteria and other microbes to theendotracheal tube, with resulting pulmonary infections.

Suction catheters are typically provided, either separately or incombination with the endotracheal tube, for removal of the accumulatedmucus. Although the function of the suction catheter is to remove themucus, excess mucus may adhere to the surface of the suction catheter,which results in impaired functioning thereof and may result in unwantedmucus remaining on the endotracheal tube. This may result incontamination of both the suction catheter and the endotracheal tube andin the inefficient operation of one or both. Furthermore, while asuction catheter is effective in removing watery mucous, the suctioncatheter is ineffective at removing mucous that has collected and driedon the wall of the endotracheal tubing, or on the catheter itself.Similar problems exist in other types of medical tubes, such asintravenous catheters, peritoneal tubing for dialysis, drainage, andirrigation.

Thus, self-cleaning and sterilizing medical tubes solving theaforementioned problems are desired.

SUMMARY OF THE INVENTION

The self-cleaning and sterilizing medical tubes decrease the tendency ofmucus and bacteria to adhere to the inner surfaces of the tubes. Thetypical medical tube defines a lumen for maintaining a passageway. Themedical tube is made from a flexible nano-composite polymer, such aspolyvinyl chloride or silicone rubber, the lower portion of the tubebeing adapted for passage or usage as desired.

Exemplary of a medical tube is an endotracheal tube and suctioncatheter. The suction catheter is a flexible tube made from the samematerial as an endotracheal tube, and can be passed through the lumen ofthe endotracheal tube while still leaving room for the passage of airthrough the endotracheal tube in an annular passage around the catheter.A fitting may be attached to the upper end of the catheter equipped withvarious ports so that the catheter may alternatively be connected to avacuum source to provide suction, an irrigation port for lavage, forpassage of an endoscope, etc.

The inner surfaces of the suction catheter and the endotracheal tube maybe made self-cleaning and sterilizing several different ways. The innersurfaces may be provided with a “lotus effect” either by laser etchingthe tubing and catheter, or a mold used to form the tubing and catheter,with a femtosecond laser, or by coating the tubing with a hydrophobicmaterial that produces the same effect. The lotus effect refers to thestructure of the lotus leaf, which is covered with tiny pillars. Waterdrops are carried up the pillars, form a spherical shape, and fall downthe pillars, carrying away any accumulated dirt. The same surface effectcan be achieved with laser etching, or by applying certain hydrophobiccoatings, such as poly (ethylene oxide).

Alternatively, the inner surfaces of the medical tube may be coated witha photocatalytic material with antimicrobial properties when exposed toultraviolet light or the photocatalytic material may be incorporatedinto the polymeric material of the tube during manufacture thereof. Suchphotocatalytic materials may include titanium oxide, silicon oxide, zincoxide, zirconium oxide, cadmium sulfate, metal oxides or combinationsthereof. A light source, such as a light emitting diode (LED), which maybe a UV LED, is attached to an upper portion of the medical tube. Lightemitted by the light source is carried by a fiberoptic bundle. Thefibers pass through the tube and illuminate the photocatalytic materialin one of two ways.

In a first embodiment, an uncoated portion of the fibers extends axiallywithin the lumen of the endotracheal tube, emitting light radially. Inthis embodiment, the lumen is lined with a UV reflective barrier and thephotocatalytic material is transparent. In a second embodiment, thefibers are coated, but terminate at different lengths, providing pointsources that are directed radially inward into the lumen of theendotracheal tube. The photocatalytic material need not be transparentin this embodiment. In either embodiment, the lumen of the suctioncatheter is also coated with a photocatalytic material or incorporatedtherein. The suction catheter is positioned outside the endotrachealtube when not in use, and may be exposed to UV or solar visible lightexternally and/or intraluminally.

Self-cleaning results from decreased adherence of biomatter to the wallsof the endotracheal tube and suction catheter upon exposure to UV light,by the photocatalytic production of substances toxic to bacteria andother microbes, and/or by exposure to UV radiation at wavelengths knownto exhibit antimicrobial activity (185 nm, 254 nm, and 265 nm). Itshould be understood that these are preferred wavelengths, and that anywavelength may be utilized, including wavelengths from the ultravioletspectra, the visible light spectra, or any other suitable spectra.

When the coating is selected from the group consisting of titaniumoxide, silicon oxide, zinc oxide, zirconium oxide, cadmium sulfate,other metal oxides and combinations thereof, ultraviolet light is usedto actuate the photocatylitic material. When these substances are dopedwith nitrogen or sulfur, visible light is used. As an alternative to thecoating, the endotracheal tube and the suction catheter may be formedfrom material that incorporates the photocatylitic material, thusforming a composite material. This allows both the endotracheal tube andthe suction catheter to exhibit the same antibacterial effects, butwithout the need of an additional coating, as the photocatalyticmaterial is already incorporated therein.

The endotracheal tube and suction catheter may also be madeself-cleaning and sterilizing by a combination of the hydrophobicsurface and the fiberoptic-photocatalytic coatings, if desired. Thescope of the present invention also extends to a tracheostomy tube,which has the same appearance and structure as the endotracheal tube,but is shorter in length, being designed for insertion into atracheostomy stoma below the larynx.

These and other features of the present invention will become readilyapparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an environmental perspective view of a self-cleaning andsterilizing endotracheal tube according to the present invention.

FIG. 2 is an environmental perspective view of the self-cleaning andsterilizing endotracheal tube according to the present invention with asuction catheter inserted therein.

FIG. 3 is a partial perspective view of the self-cleaning andsterilizing endotracheal tube according to the present invention, brokenaway and partially in section to show details of the invention.

FIG. 4 is an environmental perspective view of an alternative embodimentof the self-cleaning and sterilizing endotracheal tube according to thepresent invention.

FIG. 5A is a partial perspective view of the endotracheal tube of FIG.4, broken away and partially in section to show details thereof.

FIG. 5B shows a partial, microscopic view of a hydrophobic surfaceformed on the inner surfaces of the endotracheal tube and suctioncatheter according to an embodiment of the present invention.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed towards a self-cleaning andsterilizing medical tube, such as, a combination endotracheal tube andsuction catheter 10 that decreases the tendency of mucus and bacteria toadhere to the inner surfaces of the endotracheal tube and the suctioncatheter.

As best shown in FIG. 2, the combination 10 includes an endotrachealtube 32 and a suction catheter 18. As shown in FIG. 1, a fitting may beattached to the suction catheter with ports for connection of a vacuumtube 14 (which may have a fluted gripping surface 46) for theapplication of suction, an irrigation tube 12 for lavage, and anendotracheal tube adapter for insertion of an endoscope or other devicethrough the catheter. The endotracheal tube 32 has a lower portionadapted for insertion into a patient's trachea and defines a lumen formaintaining patentcy of the patient's airways. The diameter of theendotracheal tube lumen is large enough to permit passage of the suctioncatheter 14 therethrough and maintain the passage of air through anannular passage between the catheter 14 and the endotracheal tube 32.

In the exemplary embodiment depicted in the figures, suction catheter 14and lower portion 32 are formed from flexible nano-composite polymers,which will be comfortable for the patient, and which will not degrade orcorrode in the presence of bodily fluids. Such materials may includepolyvinyl chloride or silicone rubber. Further, as best shown in FIG. 1,the lower end of the endotracheal tube 32 is beveled, allowing for easyand comfortable insertion within the patient's trachea, the lower end 30of the suction catheter 18 extending through the lower end ofendotracheal tube 32. It should be understood that the endotracheal tubemay be shaped, sized or formed from materials adapted for use inmaintaining the patient's airways, and that the scope of the presentinvention also extends to a tracheostomy tube, which has the samestructure as the endotracheal tube 32, but is shorter in length, beingadapted for insertion through a tracheosotmy stoma below the larynx.

The endotracheal tube 32 may be made self-cleaning and sterilizing byproviding both the outer surface 32 or the inner surface 44 of the tube32 defining the lumen with a hydrophobic surface. Similarly, the suctioncatheter 18 may be made self-cleaning and sterilizing by providing boththe outer surface 18 and the inner surface 34 defining the lumen of thesuction catheter 18 with a hydrophobic surface in order to reduce thetendency of mucus and bacteria to adhere thereto.

Such a hydrophobic surface may be formed to exhibit the “lotus effect.”The lotus effect refers to the structure of the lotus leaf, which iscovered with tiny pillars. Water drops are carried up the pillars, forma spherical shape, and fall down the pillars, carrying away anyaccumulated dirt. Such a surface is shown in the microscopic view ofFIG. 58, with alternating rows of peaks 60 and valleys 62 defining thepillars. The hydrophobic surface may be formed by laser etching theouter surfaces as well as the interior surfaces 44 and 34 of the tube 32and the catheter 18, respectively, with a femtosecond laser formingperpendicular lines, or by shaping a mold for extrusion or injectionmolding of the tube 32 and catheter 18 with femtosecond laser pulses.Alternatively, the hydrophobic surface may be formed by coating theinner surfaces 44 and 34 with a hydrophobic material, such as poly(ethylene oxide), which forms chains of polymer defining the pillars inthe lumens of the endotracheal tube 32 and suction catheter 18.

Alternatively, the outer and inner surfaces, either individually orjointly, may be coated with a photocatalytic material with antimicrobialproperties when exposed to ultraviolet light, or other selective rangesof electromagnetic radiation. Such antibacterial coating materials mayinclude, for example, titanium oxide, silicon oxide, zinc oxide,zirconium oxide, cadmium sulfate, other metal oxides or combinationsthereof. It is well known that doping the above materials with nitrogenor sulfur allows for photocatalysis thereof in the presence of solar orvisible light. It should be understood that the photocatalytic surfacemay be combined with the hydrophobic surface of FIG. 5B.

As will be described below, a light source is provided for activatingthe photocatalytic material. When the coating is selected from the groupconsisting of titanium oxide, silicon oxide, zinc oxide, zirconiumoxide, cadmium sulfate, other metal oxides and combinations thereof,ultraviolet light is used to actuate the photocatylitic material. Whenthese substances are doped with nitrogen or sulfur, visible light isused. As an alternative to the coating, endotracheal tube 32 and suctioncatheter 18 may be formed from material that incorporates thephotocatalytic material, thus forming a composite material. This allowsboth the endotracheal tube 32 and the suction catheter 18 to exhibit thesame antibacterial effects, but without the need of an additionalcoating, as the photocatalytic material is already incorporated therein.

In order to provide for photocatalysis within the endotracheal tube 32,an illumination source 22 is mounted to the exterior of the endotrachealtube 32 by a bracket attached to the tube 32 by an arm extending from anupper portion of the tube 32. The illumination source 22 may comprise anLED. The illumination source 22 may comprise a source of ultravioletlight, such as one or more ultraviolet light emitting diodes. Theillumination source may further comprise a light source capable ofemitting ultraviolet light at wavelengths known to exhibit antimicrobialactivity, such as 185 nm, 254 nm and 265 nm, or at wavelengths known toinduce optimal photocatalytic activity in the particular coating used,such as 254 nm for titanium dioxide. A power cord 20 is provided forconnection with a suitable source of electrical current.

A fiberoptic bundle is further provided, with each optical fiber havingan upper end and a lower end. The upper ends 26 thereof are in directoptical communication with the illumination source 22, and are shown inFIG. 2 as being bundled together within fiberoptic cable harnesses 24.The fibers pass through the endotracheal tube 32 and provideillumination to the photocatalytic coating in one of two ways.Alternatively, the illumination source 22 may be located at the proximalend of the tube 32 (i.e. as opposed to being embedded in tube 32) andhave sufficient light source to transmit light through the entire tube.

In the embodiment shown in FIG. 3, the lower ends 36 of the opticalfibers are uncoated, and extend axially along the inner wall 44 of theendotracheal tube 32. In this embodiment, the light projects along asubstantially radial direction through the walls of the optical fibers.In this embodiment, the photocatalytic coating is transparent, and a UVreflector 38 is disposed between the fibers 36 and the exterior of thetube 32.

Alternatively, as shown in FIGS. 4 and 5A, optical fibers may havedifferent lengths with the lower ends 42 of the optical fibers 40 beingdirected radially to form point sources of light directed into the lumenof the tube 32. In this embodiment, the fibers are coated throughouttheir length, and may be attached to or embedded within the wall of thetube 32. In this embodiment, there is no UV reflector disposed in thewall of the tube 32, and the photocatalytic coating need not betransparent. Alternatively, fibers may be located at the proximal end ofthe tube and transmit the light source to the distal end of the tube.

The tube 32 is rendered self-cleaning and sterilizing by illuminatingthe photocatalyst, either through decreasing adherence of biomatter tothe walls of the tube 32 by UV radiation, by production of substancestoxic to bacteria through photocatalytic activity, and/or by irradiationwith UV light at wavelengths known to exhibit antimicrobial activity.

When not in use, the suction catheter 18 is preferably removed from theendotracheal tube 38. The suction catheter 14 may be sterilized throughirradiation with ultraviolet light externally and/or intraluminally, orby solar or visible light when the photocatalyst has been doped withnitrogen or sulfur. Further, although shown as being applied to anendotracheal tube, it should be understood that the above arrangementmay further be used with a tracheostomy tube or the like.

It will be understood that the tube 32 may be rendered self-cleaning andsterilizing through a combination of a hydrophobic surface exhibitingthe lotus effect and through a fiberoptic endotracheal tube illuminatinga photocatalyst, if desired. Further, it should be understood that theendotracheal tube shown in the Figures is for exemplary purposes only,and that the present invention may be applied to any medical tube.Examples include: arterial line and angiocatheter; nasal cannula;intravenous catheter; PICC Line (peripherally inserted centralcatheter); ventriculoperitoneal shunting tubing; ear tubes; chest cavitydrainage tubes; pericardiocentesis catheter; biliary drainage tube;various gastric (G), nasogastric (NG) and nasojejunal (NJ) tubes forfeeding, drainage and irrigation; peritoneal tubing for dialysis,drainage, and irrigation; and other similar medical tubes.

It is to be understood that the present invention is not limited to theembodiments described above, but encompasses any and all embodimentswithin the scope of the following claims.

We claim:
 1. A self-cleaning and sterilizing medical tube, comprising:an elongate tube formed of flexible nano-composite polymer materialhaving an upper portion and a lower portion, the tube defining a lumen,the lower portion being adapted for insertion into a patient body inorder to create a passageway; and means for rendering the tubeself-cleaning and sterilizing in order to prevent narrowing of the lumenand buildup of mucous and bacteria in the lumen, wherein the means forrendering the tube self-cleaning and sterilizing includes a hydrophobicsurface formed by femtosecond laser etched perpendicular lines formed inthe surface and exhibiting a lotus effect formed in the lumen of thetube.
 2. The self-cleaning and sterilizing medical tube according toclaim 1, wherein said hydrophobic surface includes a coating formed fromchains of poly (ethylene oxide) disposed in the lumen of said tube. 3.The self-cleaning and sterilizing medical tube according to claim 1,including a light source, wherein said light source comprises a sourceof ultraviolet light.
 4. The self-cleaning and sterilizing medical tubeaccording to claim 3, wherein said source of ultraviolet light emits UVradiation at an antimicrobial wavelength selected from the groupconsisting of 185 nm, 254 nm, and 265 nm.
 5. The self-cleaning andsterilizing medical tube according to claim 3, wherein said light sourcecomprises an LED.
 6. The self-cleaning and sterilizing medical tubeaccording to claim 3, wherein said light source comprises an ultravioletLED.
 7. The self-cleaning and sterilizing medical tube according toclaim 1, further including fibers extending into the lumen of the tube,the fibers include an uncoated portion extending axially within thelumen of the tube, the uncoated portion emitting light radially into thelumen.
 8. The self-cleaning and sterilizing medical tube according toclaim 7, further comprising a UV reflector disposed between the uncoatedportion of the fibers and an exterior surface of the tube.
 9. Theself-cleaning and sterilizing medical tube according to claim 2, whereinsaid photocatalytic coating is transparent.
 10. The self-cleaning andsterilizing medical tube according to claim 1, further including fibersextending into the lumen of the tube, wherein the fibers are coated andhave different lengths, the fibers having ends directed radially intothe lumen of the tube, defining point sources of light.
 11. Aself-cleaning and sterilizing medical tube, comprising: an elongate tubeformed of flexible nano-composite polymer material having an upperportion and a lower portion, the tube defining a lumen, the lowerportion being adapted for insertion into a patient's body in order tomaintain patentcy of the passageway; and means for rendering the tubeself-cleaning and sterilizing in order to prevent narrowing of the lumenand buildup of mucous and bacteria in the lumen, wherein the means forrendering the tube self-cleaning and sterilizing comprises: i) a lightsource mounted on said tube; ii) a fiberoptic bundle having fibersextending into the lumen; and iii) a photocatalyst coated on the innersurface defining the lumen of the tube.
 12. A self-cleaning andsterilizing medical tube, comprising: an elongate tube formed offlexible nano-composite polymer material, the elongate tube including aphotocatalytic material having antimicrobial properties incorporatedinto the tube, the tube having an upper portion and a lower portion, thetube defining a lumen, the lower portion being adapted for insertioninto a patient's body in order to maintain patentcy of the passageway; alight source mounted on the tube; a fiberoptic bundle having fibersextending into the lumen, whereby the tube is self-cleaning andsterilizing when exposed to the light source thereby inhibiting thenarrowing of the lumen and buildup of mucous and bacteria in the lumen.13. The self-cleaning and sterilizing endotracheal tube according toclaim 12, wherein said light source comprises a source of ultravioletlight.